21 Dec
2009
21 Dec
'09
2:04 a.m.
On Sat, 19 Dec 2009, Tony Duell wrote:
[Repairing a transistor]
Oh, that nothing ;-)) Have you ever "repaired" an EPROM with melted and
broken bond wires?
Some years ago I had an EPROM which I wanted to read out (with a very
simple programmer without any safety circuits)... I put it in the wrong
way, so the bolt wire for Vcc was open-circuit after that :-(( So I tried
to break the glass window and managed to break some more wires.
Oh well... So I took that EPROM, put it in a real good programmer, took a
microscope, three more hands ;-), some very fine needles etc. I connected
the needles (with a wire) to the programmer socket where the EPROM had a
broken wire, pressed the needles (by hand!) onto the bonding pad of the
EPROM chip and (with the help of another hand) triggered the read-out
process. I think I managed to correctly read the contents after the fifth
try.
BTW bond wires look so thick and sturdy under a microscope until you see
the needle right next to them...
Christian
Heh! That's beautiful. In a late-night,
long-hours, weekend work
situation I did that once on one pin of a 386EX using a Dremel tool to
I've done that sort of thing to PROMs and PAls that have lost the odd
pin.